The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. In this regard, wireless communication has become increasingly popular in recent years due, at least in part, to reductions in size and cost along with improvements in battery life and computing capacity of mobile electronic devices. As such, mobile electronic devices have become more capable, easier to use, and cheaper to obtain. Due to the now ubiquitous nature of mobile electronic devices, people of all ages and education levels are utilizing mobile terminals to communicate with other individuals or contacts, receive services and/or share information, media and other content.
Communication networks and technologies have been developed and expanded to provide robust support for mobile electronic devices. For example, the Worldwide Interoperability for Microwave Access (WiMAX), is a telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. The evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) is also currently being developed. The E-UTRAN, which is also known as Long Term Evolution (LTE) or 3.9G, is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards. In a typical network configuration mobile users communicate with each other via communication links maintained by the network. In this regard, for example, an originating station may typically communicate data to network devices in order for the network devices to relay the data to a target station.
Recently, efforts have been made to provide for device to device communication. More particularly, device to device communication sharing the same band that a communication network such as a cellular network uses may be desirable. Several mechanisms for enabling device to device communications in this way have been developed recently. For example, Hiperlan 2, Tetra, WLAN (wireless local area network), WiMAX, and TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) are examples in which such mechanisms have been employed.
In Hiperlan 2, a mobile terminal or user equipment (UE) associated with a first user may send a resource request (e.g., several orthogonal frequency division multiplexing (OFDM) symbols=slots) for direct communication with another UE to a central controller. After receiving a resource grant, the UE of the first user may transmit to the UE of the other user in the granted slots within the direct link phase in a media access control (MAC) frame. If the UE of the other user wants to transmit to the UE of the first user, the UE of the other user also has to reserve slots for such communication. In one instance, in an acknowledged mode, the central controller reserves slots for the acknowledgements of the other UE. Hiperlan 2 also enables a UE to request a fixed slot allocation. However, the allocation is always for a single UE, so the central controller as well as other UEs in a direct mode cannot transmit at the same time. Accordingly, this does not make efficient use of available radio resources since each UE has to reserve slots for each and every transmission which results in high signaling load. Additionally, using fixed slot allocation the number of direct links in the subnet is limited and only full OFDM symbols can be reserved, which may create a excessively large usage of system bandwidth of, for example, 100 MHz with 2048 subcarriers (e.g., assuming 1600 usable subcarriers and 64QAM modulation this equals to 8 kb for one OFDM symbol, but for example a TCP/IP acknowledgement packet has only a size of 320 b).
Tetra enables the reservation of several frequency channels for device to device communication. However, the fixed allocation of channels for device to device communication reduces the amount of resources available for base station to UE communication. WLAN enables a UE to sense a communication medium and, if the medium is free or available, the UE transmits. However, the access point (AP) has no direct ability to control the device to device links. A proposal has been made with respect to WiMAX to reserve a zone (e.g., several full OFDM symbols) for device to device communication. However, only full OFDM symbols can be reserved which, as indicated above, may be too much for a typical system bandwidth.
In light of the issues discussed above, it may be desirable to provide a mechanism for enabling an improved coordination of device to device communications that may address at least some of the problems described.